ATLANTA , Georgia -LRB- CNN -RRB- -- Sixty-four cases of measles have been diagnosed in the United States this year , the most in seven years , according to the Center for Disease Control and Prevention .

Measles is a respiratory disease whose familiar symptom is red blotches on the skin .

In all but one of the cases , the people who contracted measles had not been vaccinated . Some were too young to have gotten the shots , which are administered from 12 to 15 months of age .

The CDC released the statistics Thursday to `` serve as a reminder that measles can and still does occur in the U.S. Ongoing measles virus transmission was declared eliminated in the U.S. in 2000 , but the risk of cases and outbreaks from imported disease remains , '' the organization said in a news release . Interactive : More about measles ''

In 54 of this year 's cases the victims imported the measles from other countries , the CDC said .

Dr. Anne Schuchat , the director of the CDC 's National Center for Immunization and Respiratory Diseases , said many of the imported cases came from European nations and Israel . Watch more on the measles outbreak ''

`` Many people have forgot about measles in the United States , '' she said Schuchat at a news conference Thursday . `` It is very important for travelers heading off to Europe to make sure their immunizations are up to date . ''

The cases were reported in nine states , it said , and cases are being treated in Wisconsin , Arizona , Michigan and New York .

Measles is a viral disease that can be deadly if not treated . The 64 patients ranged in age from 5 months to 71 years . Fourteen patients were hospitalized but no deaths were reported . E-mail to a friend

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CDC : 64 confirmed measles cases in nine states since January

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64 patients ranged in age from 5 months to 71 years

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63 of the 64 were unvaccinated or had unknown vaccination status

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Highest number reported for same time period since 2001